package rsa;

/**
 * Created by csmd on 2017/9/14.
 */
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.util.HashMap;
import java.util.Map;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

@SuppressWarnings("unused")
public class rsatest {
    public static final String KEY_ALGORITHM = "RSA";
     public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
    private static final String PUBLIC_KEY = "RSAPublicKey";
     private static final String PRIVATE_KEY = "RSAPrivateKey";
    
    public static void main(String[] args) {
        Map<String, Object> keyMap;
        try {
            keyMap = initKey();

            String publicKey = getPublicKey(keyMap);
            System.out.println(publicKey);

            String privateKey = getPrivateKey(keyMap);
            System.out.println(privateKey);
        } catch (Exception e) {
            e.printStackTrace();
        } 
    }

    public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        byte[] publicKey = key.getEncoded();
        return encryptBASE64(key.getEncoded());
    }

    public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        byte[] privateKey =key.getEncoded();
        return encryptBASE64(key.getEncoded());
    } 
          
     public static byte[] decryptBASE64(String key) throws Exception { 
        return (new BASE64Decoder()).decodeBuffer(key);               
    }                                 
                           
                public static String encryptBASE64(byte[] key) throws Exception {               
        return (new BASE64Encoder()).encodeBuffer(key);               
    }       
                
    public static Map<String, Object> initKey() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();

        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();

        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);

        return keyMap;
    }
}
